# GA4 Spy

> Reverse-engineer any GA4 or Firebase App configuration from just its public Measurement ID — audit key events, consent mode, Google Signals, enhanced ecommerce, and cross-domain settings.

GA4 Spy inspects publicly exposed GA4 and Firebase config so you can audit your own tracking setup or benchmark competitors. Track properties over time, get diffs when something changes, and receive email/Slack/Teams alerts.

## Pages

- [Home](/): Scan any GA4 (G-XXXXXXXXXX), GTM container or Firebase App ID and see its full configuration.
- [GTM Spy](/gtm): Inspect any Google Tag Manager container from a URL or GTM-XXXXXXX ID — tags, triggers, variables, consent, version history and diffs.
- [GA4 Spy](/ga4): Audit any Google Analytics 4 setup from a URL or measurement ID — key events, enhanced measurement, Consent Mode, Google Signals.
- [Firebase App Spy](/firebase): Inspect the Google Analytics for Firebase configuration of an app from its Firebase App ID.
- [Plans & support](/plans): Plans for tracking more properties, faster scan cadence, and shared alerts.
- [API documentation](/docs/api): REST API for properties, scans, snapshots, diffs and alerts (Spy and Agency plans).
- [MCP documentation](/docs/mcp): Upcoming Model Context Protocol server for AI agents (Spy and Agency plans).
- [WebMCP documentation](/docs/webmcp): In-browser tools exposed via navigator.modelContext for browser agents (free).
- [Legal](/legal): Legal notice, privacy policy, and cookies.

## Markdown versions (for LLMs)

- [/plans.md](/plans.md): Plans, prices and feature matrix in plain Markdown.
- [/docs/api.md](/docs/api.md): Full REST API reference in plain Markdown.
- [/docs/mcp.md](/docs/mcp.md): MCP server reference in plain Markdown.
- [/docs/webmcp.md](/docs/webmcp.md): WebMCP (navigator.modelContext) reference in plain Markdown.